<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			*{
				margin: 0;
				padding: 0;
			}
			div.wp{
				margin: 50px auto 0;
				width: 500px;
				height: 500px;
				border: 1px solid red;
				position: relative;
			}
			
			/*ie7及以下不支持*/
			.img1{
				position: absolute;
			    top: 0;
			    right: 0;
			    bottom: 0;
			    left: 0;
			    margin: auto;
			}
			/*///////////////////////////////*/
			.img2-div{
				text-align: center;
			}
			.img2-span{
				height: 100%;
				display: inline-block;
				vertical-align: middle;
			}
			.img2{
				vertical-align: middle;
			}
			
			.img3-div{
				display: table;
				text-align: center;
			}
			.img3-span{
				display: table-cell;
				vertical-align: middle;
			}
		</style>
	</head>
	<body>
		<div class="wp">
			<img class="img1" src="img/bd_logo.png" alt="" />
		</div>
		
		<div class="wp img2-div">
			<img class="img2" src="img/bd_logo.png" alt="" /><span class="img2-span"></span>
		</div>
		
		<div class="wp img3-div">
			<span class="img3-span"><img class="img3" src="img/bd_logo.png" alt="" /></span>
		</div>
		
	</body>
</html>
